Stiffening shoe counters



Dec. 10, 1963 R. HAMILTON 3,113,906

STIFFENING SHOE coUNTERs Filed oct. 12, 195e Patented Dec. 10, 1963 3,113,906 STFFENlNG SHE CGUNTERS Russell Hamilton, East Grange, NJ., assigner to The Celastic Corporation, Kearny, NJ., a corporation of Delaware Filed Oct. l2, 1956, Ser. No. 615,473 1 Claim. (Cl. 161-165) This invention relates to a new type of counter ma- -terial for stiffening and shaping the heel portions of shoes, and more particularly it relates to a method of employing :this counter material in manufacturing shoes in which the heel conforms exactly to the last.

Heel counters in the past have been made of flat pieces of leather which are lasted into shape during the shoe-making operations, but these types of counters lack the necessary stiffness unless they are made of thick sections, in which event, the leather must be softened by soaking in Water for long periods prior to their incorporation into the shoe, and then must be held in place by an adhesive to eliminate looscness in the upper and the lining. ln addition to the above-mentioned disadvantages of leather counters, they increase the bulkiness and the weight o-f the shoes, they do not readily conform to the complex curves of the last, and ythey tend to soften when the shoe subsequently comes into contact with water. If one attempts to use thin leather sections combined with an impregnated fabric stitfener, or to use a fabric stiffener alone, it is found to be almost impossible to insert the limp, solvent-treated fabric into the pocket formed by the shoe parts without rolling o-r folding the thin skived edge, and thereby destroying the smooth surface of the finished shoe. Furthermore, `when the impregnated fabric is treated with a solvent it becomes so soft and limp that it faithfully reproduces every imperfection in the last and in the Iassembly `of the heel and insole parts, thus accentuating, rather than hiding, the imperfection in the finished shoe. Moreover, `a well made shoe exhibits a sharp corner where the upper joins the heel, and it is almost impossible to attain .such -a corner with a limp solventtreated fabric counter. A more recent innovation is the use of preshaped counters of fiberboard leather, polyethylene, or polyethylene laminated to a fabric. 'I'hese preshaped counters are not made in every conceivable size, nor even, in most cases, as Ia right-hand or a left-hand counter. Thus, a shoe employing such a counter often has a somewhat misshapen or loosely fitting heel because the shoe did not conform to the last. In shoes such a pumps or loafers, it is, of course, essential that the heel is properly shaped since this is the principal means for keeping the shoe on the foot.

A preformed counter material, such as that described and claimed in U.S. Patent 2,734,289 issued to W. H. Heaton and R. W. Morse on February 14, 1956, or U.S. Patent 2,738,600 issued to E. L. Shultz on March 20, 1956, is not completely desirable because the preformed shape, while it does bridge over imperfections in the last and in the assembly of the shoe parts, does not conform to the shoe last unless the preformed counter and the last happen to be the same size. At the present time, it is common practice to make preformed counters in three sizes only, while the last may be in any of the sizes of shoes sold today. Thus, in most instances, the last and the preformed counter do not match, and the resulting shoe is not a perfect reproduction of the last. Only by the use of a flat counter, which is pulled to the last of the shoe and formed `at that time, may a perfect lasting be accomplished every time, regardless of fine differences in the placement, size, and countour of the insole, the upper materials, and the last.

It is an object of this invention to provide method of making a shoe having a counter which is a laminate of la hlm-forming thermoplastic material and an impregnated fabric stiener, and which is capable of conforming to any shoe last. It is a specific object of this invention to provide a flat counter material which may be applied to any shoe last to form `a counter which conforms exactly to the last without duplicating minor imperfections in the last or in the assembly of shoe parts. Other objects will appeaiin the more detailed description of the invention which follows.

The above objects are accomplished by providing a stitfenable shoe counter material which is a hat laminate of one layer of a film-forming thermoplastic material, preferably polyethylene, 0.00 l-O.0l0` inch in thickness and bonded on each side to a lightweight fabric, preferably cotton flannel, impregnated with a polymer-ic material capable of being stiifened by the action of a solvent for the material. A suitable impregnating material is 56%- l0\0% by weight of a vinyl polymer, preferably, a mixture of l-3 parts by weight of polystyrene and l part by weight `of a high styrene/ low butadiene copolymer. rEhe shoe counter, after being cut to size, skived, notched, and treated with -a solvent for the impregnating resin, is inserted into the heel portion of a shoe, pulled into exact contact with the contour of the last, and, after being folded around the bottom of the heel to form a heel seat with a sharp corner, allowed to stitfen by evaporation of the solvent.

The stilfenable shoe counter material of this invention is illustrated in the 4drawing which shows a cross-sectional view of a flat laminate of this invention. The laminate il@ is made-up of a central layer of a film-forming thermoplastic material 1l and upper :and lower fabric layers l2 and 13 respectively which are impregnated with a polymerio material.

The preferred, impregnated fabric is made by the process described :and claimed in U.S. Patent 2,760,884 issued to G. L. Graf on AugustV 28, 1956, and in copending patent applications Serial No. 445,184, filed by C. E. Hendricks on July 22, 1954, now Patent No. 2,805,962, and Serial No. 502,220, filed by G. L. Graf on April 18, 1955, now Patent No. 2,923,641. Alternatively, other ty'pes of impregnated fabrics, such as cotton flannel impregnated with nitrocellulose, or other known stiifening materials capable of being stiffened by the action of a solvent for the material, may be employed in the process of this invention. The fabrics impregnated with -a latex of polystyrene and a copolymer of styrene/butadiene are preferred over other impregnated materials because they provide a higher stiffness per` unit weight of fabric, and, therefore, are lighter than the other impregnated materials.

The film-forming thermoplastic material employed as the central layer 11 of the laminate l0 may be a polyolefin, a polyamide, `a polyester, or other similar material, although polyethylene is preferred because of its stiffness, economy, and fabricability. The central lay'er of thermoplastic material may be laminated to the two impregnated fabrics by any known procedure, yalthough extrusionlamination is preferred. Extrusion-lamination is accomplished by extruding molten thermoplastic material in the form of a sheet between twopieces of the impregnated fabric described above. By applying pressure to the two fabrics, the molten or softened thermoplastic material is tightly bonded to the libe-rs of the fabric and a thin three-layer laminate is produced. Any other method of bonding the thermoplastic material to the impregnated fabric may also be used.

The fabric, prior to impregnation, may be any type of fibrous sheet material such as textiles, felts, or papers, but the preferred material is cotton ilannel having a twill u or basket weave, a thickness caliper of 0020-0105 inch, and a weight of 0.16-0.86 pound per square yard.

The following example illustrates the method of incorporating the above-described counter into the heel prtion of a shoe.

Example A laminate of a central layer of polyethylene, 0.0024 0.004 inch thick, and two outside layers of cotton flannel, impregnated with a polymeric material, were laminated into a flat sheet for use as a counter material. The polymeric impregnating material amounted to about 70% by Weight of the untreated annel and was formed of a mixture of 3 parts of polystyrene to 1 part of an 80/ 20 copolymer of styrene/butadiene. One of Ythe liannel pieces was a heavier grade Ithan the other, the heavier grade weighing about 0.34 pound per square yard prior to .impregnation and the lighter grade weighing about 0.16 pound per square yard prior to impregnation. The laminate was then blanked to the size and shape of the ldesired counter and skived down to the polyethylene on the side of the heavy grade impregnated fabric, and notched along the edge which would form the heel seat. The at, skived counter was dipped into a solvent consisting of 91% by weight of toluol and 9% by weight of naphtha, The wet counter was then inserted into the counter pocket between the upper and the lining with the Iskived side next to the upper, the stiffness of the polyethylene preventing the edge of the counter from rolling or folding. About one-half inch of the upper and the notched portion ofV the counter was left for the heel seat. The last was inserted into the shoe and the upper was tacked to the last and to the end of the insole. The -upper was then pulled over the last and tacked in place. The notched portion was folded over the heel and insole and fastened in place, the polyethylene providing sucient stiffness to cause the fold to be a sharp corner. After -7 days the heel portion was examined and found to be lan exact reproduction of the shape of the last with sucient rigidity to maintain that shape, and yet suiiciently exible to be comfortable. The bond between the counter and the upper and the bond between the counter and the quarter lining was excellent. The outer surface of the shoe was smooth and free of any imperfections Which might have been present in the last or the assembly of the parts of the shoe heel, and the corner at the heel seat was sharp. Other suitable counter materials have been made by employing an impregnating Cil 3. resin containing 1-3 parts of polystyrene per 1 part of :an /20 copolymer of styrene/butadiene.

The advantages of this type of counter material are:

(1) That the counter is not premolded,

(2) The impregnating mediumfurnishes a much stronger bond than any other known counter adhesive between the counter and the upper or the lining,

(3) That the counter may be stiffened by the action of a solvent for the impregnating medium in the fabric,

(4) The flat counter material can be shaped on the last to conform exactly to contour of the last,

(5) The counter is waterproof and will not soften nor break under normal usage, and

(6) The counter is cheaper, lighter, yand less bulky than other `known counters of high quality and of comparable stiffening ability.

I claim:

-A at `counter material for shoes comprising a threel-ayered laminate, the central layer being a film-forming thermoplastic polymeric material 0001-0010 inch in thickness, and each of the two outside layers being a lightweight fabric impregnated with a latex of polystyrene and a copolymer of styrene/ butadiene adapted simultaneously to be rendered adhesive and highly flexible when soaked by a solvent for said latex and capable of being stilened by the evaporation of said solvent for said latex.

References Qited in the iile of this patent UNITED STATES PATENTS 749,267 Davis lan. 12, 1904 2,277,941 Almy Mar. 3l, 1942 2,541,748 Daly Feb. 13, 1951 2,541,761 Harrison Feb. 13, 1951 2,569,764 lonas O'ct. 2, 1951 2,572,184 Newton Oct. 23, 1951 2,584,632 Southwick Feb. 5, 19-52 2,598,090 Yung et al. May 27, 1952 2,611,726 Harrison Sept. 23, 1952 2,616,821 Harrison Nov. 4, 1952 2,639,240 Ehle May' 19, 1953 2,684,540 Levy July 27, 1954 2,734,289 Heaton et al Feb. 14, 1956 2,758,045 Heaton et al. Aug. 7, 1956 FOREIGN PATENTS 501,208 Canada Apr. 6, 1954 

